Merge tag 'apparmor-pr-2019-06-18' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor bug fixes from John Johansen:
- fix PROFILE_MEDIATES for untrusted input
- enforce nullbyte at end of tag string
- reset pos on failure to unpack for various functions
* tag 'apparmor-pr-2019-06-18' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: reset pos on failure to unpack for various functions
apparmor: enforce nullbyte at end of tag string
apparmor: fix PROFILE_MEDIATES for untrusted input
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 1ce4e9b..b5b4b81 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -213,7 +213,16 @@ static inline struct aa_profile *aa_get_newest_profile(struct aa_profile *p)
return labels_profile(aa_get_newest_label(&p->label));
}
-#define PROFILE_MEDIATES(P, T) ((P)->policy.start[(unsigned char) (T)])
+static inline unsigned int PROFILE_MEDIATES(struct aa_profile *profile,
+ unsigned char class)
+{
+ if (class <= AA_CLASS_LAST)
+ return profile->policy.start[class];
+ else
+ return aa_dfa_match_len(profile->policy.dfa,
+ profile->policy.start[0], &class, 1);
+}
+
static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile,
u16 AF) {
unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index 01957ce..8cfc9493 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -219,16 +219,21 @@ static void *kvmemdup(const void *src, size_t len)
static size_t unpack_u16_chunk(struct aa_ext *e, char **chunk)
{
size_t size = 0;
+ void *pos = e->pos;
if (!inbounds(e, sizeof(u16)))
- return 0;
+ goto fail;
size = le16_to_cpu(get_unaligned((__le16 *) e->pos));
e->pos += sizeof(__le16);
if (!inbounds(e, size))
- return 0;
+ goto fail;
*chunk = e->pos;
e->pos += size;
return size;
+
+fail:
+ e->pos = pos;
+ return 0;
}
/* unpack control byte */
@@ -272,7 +277,7 @@ static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
char *tag = NULL;
size_t size = unpack_u16_chunk(e, &tag);
/* if a name is specified it must match. otherwise skip tag */
- if (name && (!size || strcmp(name, tag)))
+ if (name && (!size || tag[size-1] != '\0' || strcmp(name, tag)))
goto fail;
} else if (name) {
/* if a name is specified and there is no name tag fail */
@@ -290,62 +295,84 @@ static bool unpack_nameX(struct aa_ext *e, enum aa_code code, const char *name)
static bool unpack_u8(struct aa_ext *e, u8 *data, const char *name)
{
+ void *pos = e->pos;
+
if (unpack_nameX(e, AA_U8, name)) {
if (!inbounds(e, sizeof(u8)))
- return 0;
+ goto fail;
if (data)
*data = get_unaligned((u8 *)e->pos);
e->pos += sizeof(u8);
return 1;
}
+
+fail:
+ e->pos = pos;
return 0;
}
static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
{
+ void *pos = e->pos;
+
if (unpack_nameX(e, AA_U32, name)) {
if (!inbounds(e, sizeof(u32)))
- return 0;
+ goto fail;
if (data)
*data = le32_to_cpu(get_unaligned((__le32 *) e->pos));
e->pos += sizeof(u32);
return 1;
}
+
+fail:
+ e->pos = pos;
return 0;
}
static bool unpack_u64(struct aa_ext *e, u64 *data, const char *name)
{
+ void *pos = e->pos;
+
if (unpack_nameX(e, AA_U64, name)) {
if (!inbounds(e, sizeof(u64)))
- return 0;
+ goto fail;
if (data)
*data = le64_to_cpu(get_unaligned((__le64 *) e->pos));
e->pos += sizeof(u64);
return 1;
}
+
+fail:
+ e->pos = pos;
return 0;
}
static size_t unpack_array(struct aa_ext *e, const char *name)
{
+ void *pos = e->pos;
+
if (unpack_nameX(e, AA_ARRAY, name)) {
int size;
if (!inbounds(e, sizeof(u16)))
- return 0;
+ goto fail;
size = (int)le16_to_cpu(get_unaligned((__le16 *) e->pos));
e->pos += sizeof(u16);
return size;
}
+
+fail:
+ e->pos = pos;
return 0;
}
static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
{
+ void *pos = e->pos;
+
if (unpack_nameX(e, AA_BLOB, name)) {
u32 size;
if (!inbounds(e, sizeof(u32)))
- return 0;
+ goto fail;
size = le32_to_cpu(get_unaligned((__le32 *) e->pos));
e->pos += sizeof(u32);
if (inbounds(e, (size_t) size)) {
@@ -354,6 +381,9 @@ static size_t unpack_blob(struct aa_ext *e, char **blob, const char *name)
return size;
}
}
+
+fail:
+ e->pos = pos;
return 0;
}
@@ -370,9 +400,10 @@ static int unpack_str(struct aa_ext *e, const char **string, const char *name)
if (src_str[size - 1] != 0)
goto fail;
*string = src_str;
+
+ return size;
}
}
- return size;
fail:
e->pos = pos;